Image capture apparatus and image signal processing apparatus

ABSTRACT

An image capture apparatus includes an image capture unit that has a plurality of unit pixels each including a plurality of photo-electric conversion units per condenser unit, and a recording unit that records captured image signals, which are captured by the image capture unit and are respectively read out from the plurality of photo-electric conversion units, and the recording unit records identification information which allows to identify each photo-electric conversion unit used to obtain the captured image signal in association with that captured image signal.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a technique for acquiring capturedimage signals for stereoscopic vision, and generating image signals.

2. Description of the Related Art

In recent years, stereoscopic images and stereoscopic image-relateddevices such as 3D movies and 3D displays have rapidly prevailed.Capturing of stereoscopic images is conventionally done using a filmcamera or the like. However, along with the popularization of digitalimage capture apparatuses such as digital cameras and digital videocameras, images as generation sources of stereoscopic images arecaptured using these digital image capture apparatuses.

The following mechanism for appreciating stereoscopic images isgenerally used. That is, “right-eye image” and “left-eye image” having aparallax in a right-and-left direction are prepared in correspondencewith an image when the user views an object by the right eye and thatwhen he or she views it by the left eye, and the user views the“right-eye image” by the right eye and the “left-eye image” by the lefteye. As this method, a method of dividing an image to be appreciated tohave a parallax using a parallax barrier system, lenticular system, orthe like, and a method of controlling different images to becomeincident on the right and left eyes via right and left filters havingdifferent characteristics are known.

As an image capture method of images which can be appreciated asstereoscopic images, a method of simultaneously capturing images atdifferent view points is available.

In a solid state image sensor described in Japanese Patent Laid-Open No.58-24105, a plurality of microlenses are formed on the solid state imagesensor, and at least a pair of photodiodes are disposed in the vicinityof each of these plurality of microlenses. A first image signal isobtained from an output of one photodiode of this photodiode pair, and asecond image signal is obtained from the other photodiode. As describedin Japanese Patent Laid-Open No. 58-24105, when the first and secondimage signals obtained in this way are used as the “right-eye image” and“left-eye image” described above, stereoscopic images can beappreciated.

A solid state image sensor described in Japanese Patent Laid-Open No.2007-325139 has an arrangement in which a plurality of microlenses arealso formed on the solid state image sensor, and a plurality ofphotodiodes are disposed for each microlens. As a characteristicarrangement of Japanese Patent Laid-Open No. 2007-325139, the pluralityof photodiodes which are disposed in correspondence with one microlensare connected to each other via gates. Therefore, whether signals of theneighboring photodiodes are to be added in a pixel or they are read outwithout being added can be controlled.

Japanese Patent Laid-Open No. 2007-325139 obtains captured image signalsand focus detection signals of an image capture apparatus using thesolid state image sensor with the aforementioned arrangement. In anormal image capture mode, signals of all photodiodes are added togenerate captured image signals. In a focus detection mode, signalshaving a parallax have to be obtained. In order to obtain signals havinga parallax in the right-and-left direction, photodiodes, which neighborin an up-and-down direction, need only be connected. Also, in order toobtain signals having a parallax in the up-and-down direction,photodiodes, which neighbor in the right-and-left direction, need onlybe connected. Japanese Patent Laid-Open No. 2007-325139 presents thefollowing use method. That is, using the solid state image sensor withthis arrangement, accurate focus detection is attained usingcombinations of addition results of the photodiodes, which are suited tofocus detection of an object image, in accordance with the pattern ofthe object image.

Image signals generated by an image capture apparatus are normallyprinted on media such as paper or are displayed on a display device suchas a television, monitor, or projector when they are appreciated. Thesame applies to 2D images and 3D images.

In order to appreciate stereoscopic images, as described above, the userhas to view images having a parallax in the right-and-left direction bythe corresponding eyes. Therefore, in all the systems described in therelated art, the “right-eye image” to be appreciated by the right eyeand the “left-eye image” to be appreciated by the left eye have to beprepared.

The related art literatures explain the solid state image sensor havingthe arrangement in which the plurality of microlenses are formed on thesolid state image sensor, and a plurality of photodiodes are disposedfor each microlens. Also, as described in these literatures, a pluralityof captured image signals, which can be respectively used as the“right-eye image” and “left-eye image” displayable as stereoscopicimages, can be obtained using the solid state image sensor with sucharrangement.

However, with the inventions described in the related art literatures,although the “right-eye image” and “left-eye image” can be obtained, aparallax between the “right-eye image” and “left-eye image” often has adirection that does not allow these images to be appreciated asstereoscopic images.

That is, in the technique described in Japanese Patent Laid-Open No.58-24105, the layout of photodiode pairs at the time of design decides,in advance, the direction of a parallax of captured images.

Or in the technique described in Japanese Patent Laid-Open No.2007-325139, the direction of a parallax of captured images is decidedby combinations of addition results of photodiodes, which are selectedaccording to an object image, when signals are read out from thephotodiodes. That is, the “right-eye image” and “left-eye image”, whichare generated from signals read out from an image capture apparatus, canhave only a parallax in one direction, which is decided in advancebefore signals are read out.

Therefore, when the parallax direction of images does not match that ofthe two eyes of the user upon appreciating captured images, the usercannot recognize these images as stereoscopic images. For example, whenimages having a parallax in the right-and-left direction are displayedwhile being rotated through 90° from a normal position, the parallaxdirection of the two images changes from the right-and-left direction tothe up-and-down direction, and these images cannot be appreciated asstereoscopic images, thus posing a problem.

SUMMARY OF THE INVENTION

The present invention has been made in consideration of theaforementioned problems, and allows to generate and display, based oncaptured image signals captured using an image capture apparatus, imageshaving a parallax in a direction suited to be appreciated asstereoscopic images independently of their display directions.

The first aspect of the present invention provides an image captureapparatus comprising: image capture unit having a plurality of unitpixels each comprising a plurality of photo-electric conversion unitsper condenser unit; and recording unit configured to record capturedimage signals, which are captured by the image capture unit and arerespectively read out from the plurality of photo-electric conversionunit, wherein the recording unit records identification informationwhich allows to identify each photo-electric conversion unit used toobtain the captured image signal in association with that captured imagesignal.

The second aspect of the present invention provides an image signalprocessing apparatus generating image signals for stereoscopic visionusing captured image signals in respective photo-electric conversionunit of the above image capture apparatus, and pieces of identificationinformation respectively associated with the captured image signals.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing the overall arrangement of an imagecapture apparatus according to one embodiment of the present invention;

FIGS. 2A to 2D are schematic views for explaining the arrangements ofthe image capture apparatus and a solid state image sensor, displayangles of image signals, and combinations of signals per unit pixel,which are used in generation of image signals, in the embodiment of thepresent invention;

FIG. 3 is a schematic view showing an example of the arrangement of aunit pixel of the solid state image sensor in the embodiment of thepresent invention;

FIGS. 4A to 4D are conceptual views showing sequences of captured imagesignals and tags, which are recorded by a recording unit in theembodiment of the present invention; and

FIG. 5 is a schematic view showing an example of the arrangement of aunit pixel of the solid state image sensor in a modification of theembodiment of the present invention.

DESCRIPTION OF THE EMBODIMENTS

One embodiment of the present invention will be described in detailhereinafter with reference to the accompanying drawings. FIG. 1 is ablock diagram showing the overall arrangement of an image captureapparatus according to one embodiment of the present invention.Referring to FIG. 1, reference numeral 1 denotes an optical systemincluding optical members such as a lens and stop. Reference numeral 2denotes a mechanical shutter which intercepts light on a solid stateimage sensor (to be described below) so as to control an exposure timeof the solid state image sensor. Reference numeral 3 denotes a solidstate image sensor which converts irradiated light into an electricalsignal, and outputs it as a captured image signal. Details of the solidstate image sensor of this embodiment will be described later.

Reference numeral 5 denotes a timing signal generation circuit, whichgenerates required signals for a driving circuit 6, so as to operate thesolid state image sensor 3. Reference numeral 6 denotes a drivingcircuit for the optical system 1, mechanical shutter 2 and solid stateimage sensor 3. Reference numeral 7 denotes a signal processing circuit,which executes signal processing such as various kinds of correctionrequired for captured image signals, and generates image signals fromthe captured image signals which have undergone the signal processing.Reference numeral 8 denotes an image memory, which stores the capturedimage signals that have undergone the signal processing, and the imagesignals. Reference numeral 9 denotes a recording medium detachable fromthe image capture apparatus.

Reference numeral 10 denotes a recording circuit, which records thecaptured image signals that have undergone the signal processing on therecording medium 9. Reference numeral 11 denotes an image displaydevice, which displays the image signal that has undergone the signalprocessing. Reference numeral 12 denotes a display circuit, whichdisplays the image signals on the image display device 11. Referencenumeral 13 denotes a system controller which controls the overall imagecapture apparatus.

Reference numeral 14 denotes a nonvolatile memory (ROM). The nonvolatilememory 14 stores a program that describes a control method to beexecuted by the system controller 13, control data including parametersand tables to be used upon execution of the program, and data used forvarious kinds of correction of image signals.

Reference numeral 15 denotes a volatile memory (RAM). The volatilememory 15 stores the program, control data, and correction data, whichare transferred from the nonvolatile memory 14 storing these program anddata, and are used when the system controller 13 controls the imagecapture apparatus. Reference numeral 16 denotes a switch S0 used tocontrol a power-ON/OFF state of the image capture apparatus. Referencenumeral 17 denotes a switch S1 used to issue a start instruction ofvarious image capture preparation operations required for the imagecapture apparatus to perform an image capture operation. Referencenumeral 18 denotes a switch S2 used to issue an image capture operationstart instruction of the image capture apparatus.

Note that the aforementioned arrangement of the image capture apparatusis merely an example of the arrangement required to practice the presentinvention, and the present invention is not limited to this embodiment.For example, the above example has explained one image capture apparatuswhich incorporates an image capture unit and recording unit.Alternatively, an image capture apparatus and recording apparatus may beindependently arranged, and captured image signals acquired by the imagecapture apparatus may be recorded by the recording apparatus. Also,other components can undergo various modifications and changes withinthe scope of the spirit of the invention.

The arrangement of the solid state image sensor incorporated in theimage capture apparatus of this embodiment will be described below. FIG.2B is a schematic view showing an example of the overall arrangement ofthe solid state image sensor of this embodiment.

In this case, an axis which is parallel to the bottom surface of theimage capture apparatus is defined as an x-axis, and an axis which isperpendicular to the bottom surface of the image capture apparatus isdefined as a y-axis, when the solid state image sensor incorporated inthe image capture apparatus is viewed from the front side of imagecapture apparatus. For example, under the assumption that the solidstate image sensor is incorporated to have the side of its long side tobe parallel to the bottom surface of the image capture apparatus, anaxis parallel to the long side is defined as the x-axis, and an axisparallel to the short side is defined as the y-axis.

As shown in FIG. 2B, the solid state image sensor of this embodimentincludes (has) a plurality of unit pixels, which are arrayed in a matrixon an image capture plane as a two-dimensional plane. Assume that eachindividual unit pixel indicated by the broken line in FIG. 2B isexpressed by an address described within the broken line. For example,an address of a unit pixel of the 0th column and 1st row is expressed by(0, 1), and that of a unit pixel of the N-th column and M-th row isexpressed by (N, M).

Each individual unit pixel indicated by the broken line in FIG. 2Bconverts irradiated light into an electrical signal, and accumulates andoutputs the electrical signal. An example of the detailed arrangement ofthe unit pixel will be described below.

FIG. 3 is a schematic view showing an example of the arrangement of theunit pixel of the solid state image sensor of this embodiment. FIG. 3shows a rough layout of photodiodes PD as photo-electric conversionunits each for converting light into an electrical signal, and amicrolens ML as a condenser unit which condenses light on thephotodiodes PD. These photodiodes PD and microlens ML form one unitpixel.

As shown in FIG. 3, on each individual unit pixel, a plurality ofphotodiodes PD and a microlens ML corresponding to the unit pixel arearranged. In this case, for example, FIG. 3 illustrates a unit pixel onwhich four photodiodes PD, that is, photodiodes PD(0, 0), PD(1, 0),PD(0, 1), and PD(1, 1) are arranged for one microlens ML.

The example of the arrangement of the solid state image sensor which canpractice the present invention has been described. However, thearrangement of the solid state image sensor is merely an example of thearrangement required to practice the present invention. In practice, asolid state image sensor need only have an arrangement including aplurality of photo-electric conversion units per condenser unit. Thepresent invention is not limited to the aforementioned embodiments, andallows various modifications and changes within the scope of the spiritof the invention.

Note that in order to provide parallaxes in a plurality of directionsbetween the plurality of photo-electric conversion units included in onepixel, the number of photodiodes PD is preferably three or more.

A recording unit, which records captured image signals read out from theaforementioned solid state image sensor, will be described below usingFIGS. 2B and 2D and FIGS. 4A to 4D.

Each of D1, D2, and D3 of FIG. 2D simply illustrates an array of aplurality of photodiodes PD included in one unit pixel of the pluralityof unit pixels indicated by the broken lines in FIG. 2B, and is equal tothe unit pixel shown in FIG. 3. In FIG. 2D, the microlens ML is notshown for the sake of simplicity.

The plurality of photodiodes PD corresponding to one unit pixel areprovided with different tags as identification information, so as toallow to specify each individual photodiode PD. For example, eachindividual photodiode PD is provided with a tag which includes, asidentification information, information (position information)associated with a positional relationship of the respective photodiodesin the unit pixel. In this embodiment, a case will be exemplifiedwherein each pixel group corresponding to each unit pixel is providedwith tag information associated with a position x in the x-axisdirection and a position y in the y-axis direction like (x, y). Forexample, as shown in FIG. 3, the photodiode PD(0, 0) is provided with atag (0, 0); PD(1, 0), a tag (1, 0); PD(0, 1), a tag (0, 1); and PD(1,1), a tag (1, 1).

Alternatively, a symbol required for identification may be assigned toeach of the plurality of photodiodes PD which form each unit pixel, andmay be used as a tag. For example, an identification symbol “LD” may beassigned to the lower left photodiode PD(0, 0), an identification symbol“RU” may be assigned to the upper right photodiode PD(1, 1), and theymay be used as tags.

An image capture unit controls the solid state image sensor toaccumulate captured image signals, and individually reads out allcaptured image signals of the respective photodiodes PD (PD(0, 0), PD(1,0), PD(0, 1), and PD(1, 1)). The readout captured image signals of thephotodiodes PD(0, 0), PD(1, 0), PD(0, 1), and PD(1, 1) will berespectively referred to as Sig(0, 0), Sig(1, 0), Sig(0, 1), andSig(1, 1) hereinafter.

FIGS. 4A to 4D are conceptual views showing sequences of captured imagesignals and tags, which are recorded by the recording unit according tothis embodiment. Data to be recorded by the recording unit will bedescribed below taking, as an example, captured image signals obtainedfrom the plurality of photodiodes PD included in the unit pixel of theN-th column and M-th row, and tags assigned to these photodiodes asidentification information.

The recording unit assigns the aforementioned tags for respectivephotodiodes PD to readout captured image signals of the respectivephotodiodes PD, and saves the levels of the captured image signals andthe tags in association with each other. In this embodiment, as shown inFIG. 4A, the recording unit saves the captured image signal Sig(0, 0) ofthe photodiode PD(0, 0) assigned with the tag (0, 0), the captured imagesignal Sig(1, 0) of the photodiode PD(1, 0) assigned with the tag (1,0), the captured image signal Sig(0, 1) of the photodiode PD(0, 1)assigned with the tag (0, 1), and the captured image signal Sig(1, 1) ofthe photodiode PD(1, 1) assigned with the tag (1, 1). The data whichrecords the captured image signals obtained from the unit pixel of theN-th column and M-th row has been described. Such data are recorded incorrespondence with all unit pixels read out from the solid state imagesensor.

Note that the aforementioned tag for each photodiode PD may be assignedwith address information of each unit pixel, which is shown within thebroken line indicating each unit pixel in FIG. 2B, in addition to theidentification information. Alternatively, as shown in FIG. 4B, addressinformation of each unit pixel may be assigned to data for that unitpixel.

Alternatively, as shown in FIG. 4C, a tag indicating a storage order ofsignals in data, which records captured image signals of photodiodes PDincluded in a unit pixel in the same order for all unit pixels, may berecorded at the head of the data which records all captured imagesignals. Alternatively, as shown in FIG. 4D, all captured image signalsobtained from photodiodes PD, which are included in different unitpixels and have common identification information, may be savedtogether, and the common identification information may be recorded atthe head of the sequence as a tag.

By assigning such tag information to a captured image signal obtainedfrom each photodiode PD, a captured image signal and an address of aunit pixel can be easily specified when it is used by an arbitrary imageprocessing unit or display unit. Also, a positional relationship ofphotodiodes PD in a given PD group and photodiodes PD from which aplurality of captured image signals are obtained from a predeterminedunit pixel can be easily specified.

Using captured image signals captured by the image capture apparatuswith the aforementioned arrangement, images which can be appreciated asstereoscopic images can be generated independently of rotation angles ofthe image signals to be displayed.

Use examples of captured image signals used to obtain pairs of images(for stereoscopic vision) suited to stereoscopic vision for variousimage rotation angles from captured image signals which are saved whilebeing assigned with the tag information will be described below. Notethat in the example of the image capture apparatus of this embodiment,the signal processing circuit 7 shown in FIG. 1 is used as an imagesignal generation unit used to obtain image signals to be displayed fromcaptured image signals. As another example, image signals may begenerated by an external image signal generation unit (image signalprocessing apparatus).

C1, C2, and C3 of FIG. 2C are schematic views showing image rotationangles and images displayed at that time when these images are displayedon the image display device. A first image signal and second imagesignal shown in each of C1, C2, and C3 of FIG. 2C correspond to a pairof images having a parallax, which are generated from captured imagesignals captured and recorded by the image capture apparatus shown inFIG. 2A incorporating the solid state image sensor shown in FIG. 2B, andwhich correspond to right- and left-eye images. An axis, which overlapsthe x-axis of the pair of images, when the pair of images are displayedat a rotation angle=0°, is defined as a reference axis xv (indicated bya one-dashed chain line in FIG. 2C) of the display device. Also, let θvbe a rotation angle of a displayed image from the reference axis xv ofthe display device. The rotation angle θv is acquired from a parameterwhich is designated by an image display program and indicates a rotationangle or that which is input via, for example, an input device based ona user's instruction and indicates a rotation angle.

D1, D2, and D3 of FIG. 2D are schematic views showing combinations ofcaptured image signals, used when respective image signals of a pair ofimages having a parallax are generated, in correspondence with layoutsof photodiodes PD corresponding to the respective signals.

When image signals are to be generated, captured image signals from theplurality of photodiodes PD included in unit pixels are grouped forrespective photodiodes PD, which are divided by a line perpendicular tothe axis xv, based on the tag information. Then, an image signal whichforms one image is generated from the captured image signals of eachgroup, thereby obtaining first and second images having differentparallaxes in the x-axis direction.

An example when images generated based on captured image signalscaptured by the image capture apparatus with the arrangement shown inFIG. 2B are displayed at a landscape position will be described first.When the rotation angle θv=0° of the displayed images, as shown in C1 ofFIG. 2C, the photodiodes PD(0, 0) and PD(0, 1) are selected as a firstPD group, as indicated by the solid line in D1 of FIG. 2D, and a firstimage signal is generated using the captured image signals by the firstPD group. Also, the photodiodes PD(1, 0) and PD(1, 1) are selected as asecond PD group, and a second image signal is generated using capturedimage signals by the second PD group. Then, a first image is formed bythe first image signal obtained in this way, and a second image isformed by the second image signal, thus obtaining the first and secondimages having different parallaxes in the x-axis direction.

When the first and second images obtained in this way are used as theaforementioned “left-eye image” and “right-eye image”, images having aparallax direction suited to stereoscopic vision when the images aredisplayed at the landscape position can be generated.

Even when images are to be displayed at the landscape position, ifθv=180° (at a position opposite to the aforementioned case), thephotodiodes PD(1, 0) and PD(1, 1) can be selected as a first PD group togenerate a first image signal, and the photodiodes PD(0, 0) and PD(0, 1)can be selected as a second PD group to generate a second image signal.

An example when images generated based on captured image signalscaptured by the image capture apparatus with the arrangement shown inFIG. 2B are displayed at a portrait position will be described below.When the rotation angle θv=90° of the displayed images, as shown in C2of FIG. 2C, the photodiodes PD(0, 0) and PD(0, 1) are selected as asecond PD group, as indicated by the solid line in D2 of FIG. 2D, and asecond image signal is generated using the captured image signals by thesecond PD group. Also, the photodiodes PD(1, 0) and PD(1, 1) areselected as a first PD group, and a first image signal is generatedusing captured image signals by the first PD group. Then, a first imageis formed by the first image signal obtained in this way, and a secondimage is formed by the second image signal, thus obtaining the first andsecond images having different parallaxes in the y-axis direction.

When the first and second images obtained in this way are used as theaforementioned “left-eye image” and “right-eye image”, images having aparallax direction suited to stereoscopic vision when the images aredisplayed at the portrait position can be generated.

Even when images are to be displayed at the portrait position, ifθv=270° (at a position opposite to the aforementioned case), thephotodiodes PD(0, 0) and PD(1, 0) can be selected as a first PD group togenerate a first image signal, and the photodiodes PD(0, 1) and PD(1, 1)can be selected as a second PD group to generate a second image signal.

Finally, an example when images generated based on captured imagesignals captured by the image capture apparatus with the arrangementshown in FIG. 2B are displayed at an oblique position will be describedbelow. When the rotation angle θv=45° of the displayed images, as shownin C3 of FIG. 2C, the photodiode PD(0, 1) is selected as a first PDgroup, as indicated by the solid line in D3 of FIG. 2D, and a firstimage signal is generated using the captured image signal by the firstPD group. Also, the photodiode PD(1, 0) is selected as a second PDgroup, and a second image signal is generated using the captured imagesignal by the second PD group. Then, a first image is formed by thefirst image signal obtained in this way, and a second image is formed bythe second image signal, thus obtaining the first and second imageshaving different parallaxes in an oblique direction. At this time, sincethe number of captured image signals that can be used is reducedcompared to the portrait and landscape positions, signals by therespective PD groups may be multiplied by a desired gain when they areused. For example, in this case, since the number of captured imagesignals that can be used is reduced to ½ compared to that at theportrait or landscape position, the signals may be further multiplied bya gain of about 2×, so as to obtain the same signal level as an additionresult of the plurality of captured image signals.

When the first and second images obtained in this manner are used as theaforementioned “left-eye image” and “right-eye image”, images can begenerated that have a parallax direction suited to stereoscopic visionwhen the images are displayed at the oblique position.

Even when images are to be displayed at the oblique position, if θv=225°(at a position opposite to the aforementioned case), the photodiodePD(0, 1) can be selected as a second PD group to generate a second imagesignal, and the photodiode PD(1, 0) can be selected as a first PD groupto generate a first image signal.

Furthermore, even when images are to be displayed at an obliqueposition, if θv=315°, the photodiode PD(0, 0) can be selected as a firstPD group to generate a first image signal, and the photodiode PD(1, 1)can be selected as a second PD group to generate a second image signal.If θv=135°, the photodiode PD(1, 1) can be selected as a first PD groupto generate a first image signal, and the photodiode PD(0, 0) can beselected as a second PD group to generate a second image signal.

Note that the θv cases assuming predetermined angles have beenexemplified. Angle ranges for switching groups may be set. For example,captured image signals to be used to generate respective image signalsare selected so as to provide parallaxes to the first and second imagesin a direction closest to a direction parallel to the axis xv, inaccordance with the angle θv.

Practical examples will be described below.

0≦θv≦22.5° (around a rotation angle=0°) . . . This angle is handled asθv=0° to generate image signals.22.5°<θv<67.5° (around a rotation angle=45° at the time of clockwiserotation) . . . This angle is handled as θv=45° to generate imagesignals.67.5°≦θv≦112.5° (around a rotation angle=90° at the time of clockwiserotation) . . . This angle is handled as θv=90° to generate imagesignals.112.5°<θv<157.5° (around a rotation angle=135° at the time of clockwiserotation) . . . This angle is handled as θv=135° to generate imagesignals.157.5°≦θv≦202.5° (around a rotation angle=180°) . . . This angle ishandled as θv=180° to generate image signals.205.5°<θv<247.5° (around a rotation angle=225° at the time of clockwiserotation) . . . This angle is handled as θv=225° to generate imagesignals.247.5°≦θv≦292.5° (around a rotation angle=270° at the time of clockwiserotation) . . . This angle is handled as θv=270° to generate imagesignals.292.5°<θv<337.5° (around a rotation angle=315° at the time of clockwiserotation) . . . This angle is handled as θv=315° to generate imagesignals.337.5°≦θv≦360° (around a rotation angle=0°). This angle is handled asθv=0° to generate image signals.

The arrangement using the solid state image sensor in which fourphotodiodes PD are disposed in a 2×2 matrix per unit pixel, as shown inFIG. 3, has been exemplified so far. However, in case of such usemethod, in a unit pixel of the solid state image sensor, a larger numberof photodiodes are desirably disposed as much as possible. This isbecause, when a larger number of photodiodes are disposed, as shown inFIG. 5, first and second PD groups used to generate first and secondimage signals can be freely selected from the large number ofphotodiodes PD. Therefore, a direction of a parallax provided betweenthe “right-eye image” and “left-eye image” can be adjusted moreprecisely.

A case will be exemplified below wherein images to be displayed aredisplayed while being rotated through θv° with respect to the referenceaxis xv of the display device in FIG. 5. An axis, which is perpendicularto the reference axis xv of the display device and passes through thebarycenter of light that has passed through the microlens ML, is definedas an axis yv. At this time, photodiodes PD, which are included in oneof regions divided by the axis yv, of a plurality of photodiodes PDincluded in a unit pixel, are selected as a first PD group, andphotodiodes PD included in the other region are selected as a second PDgroup. The respective PD groups are indicated by the solid lines in FIG.5.

Captured image signals obtained from the photodiodes PD included in thefirst PD group are selected based on tags assigned to the captured imagesignals obtained from the respective photodiodes PD to generate a firstimage signal. Captured image signals obtained from the photodiodes PDincluded in the second PD group are similarly selected to generate asecond image signal.

Thus, the direction of a parallax provided between the first and secondimages can be decided more precisely, and images more suited to beappreciated as stereoscopic images upon rotating images displayed on thedisplay device can be obtained.

The aforementioned embodiment and modification are respectively suitableexamples of aspects upon practicing the present invention. The presentinvention is not limited to these embodiments, and allows variousmodifications and changes within the scope of the gist of the invention.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Application No.2011-032629, filed Feb. 17, 2011, which is hereby incorporated byreference herein in its entirety.

1. An image capture apparatus comprising: image capture unit having aplurality of unit pixels each comprising a plurality of photo-electricconversion units per condenser unit; and recording unit configured torecord captured image signals, which are captured by said image captureunit and are respectively read out from the plurality of photo-electricconversion unit, wherein said recording unit records identificationinformation which allows to identify each photo-electric conversion unitused to obtain the captured image signal in association with thatcaptured image signal.
 2. The apparatus according to claim 1, whereinsaid recording unit records pieces of different identificationinformation in association with respective captured image signals of theplurality of photo-electric conversion units in each unit pixel.
 3. Theapparatus according to claim 1, wherein the identification informationincludes position information indicating a positional relationship ofrespective photo-electric conversion unit in the unit pixel.
 4. An imagesignal processing apparatus generating image signals for stereoscopicvision using captured image signals in respective photo-electricconversion unit of an image capture apparatus according to claim 1, andpieces of identification information respectively associated with thecaptured image signals.
 5. The apparatus according to claim 4, whereinthe identification information includes position information indicatinga positional relationship of respective photo-electric conversion unitin each unit pixel.